The Don Sahong is a hydroelectric dam commissioned in 2020 on the Mekong River in Siphandone area of Champasak Province, Laos, less than two kilometers upstream of the Laos–Cambodia border.

[4] In March 2006, the Government of Laos signed a memorandum of understanding with the Malaysian engineering and construction company, Mega First Corporation Berhad, for a feasibility study of the project.

[1] On 30 September 2013, the government of Laos notified the Mekong River Commission of its intention to construct the Don Sahong Dam.

[9] In June 2014, the government of Laos agreed to have the Don Sahong Hydropower Project undergo the MRC's prior consultation process.

[24][25] The viability of these alternative routes has been questioned by government representatives of Cambodia, Thailand, and Vietnam, with the latter suggesting "it is not possible to replace the modified channels for upstream fish migration with the existing Hou Sahong".

[27] The Don Sahong Hydropower Project would pose a major threat to the Mekong River's critically endangered population of Irrawaddy dolphin.

[28] The risk is considered very high for the small resident sub-population living in the Veun Nyang/Anlong Cheuteal pool that straddles the Lao/Cambodian border, and is the only remaining dolphin population in Laos.

[28] Threats to the dolphins include the blasting of large volumes of rock from the channel, the intensive heavy industrial activity at the site, and modifications to the river flows.

Other risks identified include the long-term effects of disturbance and stress on the animals, and the demographic consequences if the sub-population near the dam was extirpated.